A water analysis device of this kind is known from WO 2016/079259 A1. The water analysis device has a cuvette chamber in which a test cuvette is arranged. The water analysis device further has a ventilation circuit for the ventilation of the cuvette chamber, whereby the formation of condensate, in particular on the test cuvette, is avoided. The ventilation circuit has a ventilation pump downstream from the cuvette chamber. The cuvette chamber has an air inlet downstream from the ventilation pump. A device housing is provided which forms the cuvette chamber, and a cap arrangement is provided which closes and protects the cuvette chamber against atmospheric fluids. The fluid-tight sealing of the cap arrangement against the device housing is important in order for no air or dust that comes along with air and no humidity to penetrate the cuvette chamber or the interior of the device, because this causes severe disturbances to the scattering measurement. The cap arrangement must be easy to open so that simple access to the cuvette chamber and the test cuvette is possible.
The task of the invention is to create a water analysis device with a cap arrangement that offers a reliable sealing and an easy operability.